Numerical simulation of flash reduction in a drop tube reactor with variable temperatures

• Published in: International journal of minerals, metallurgy and materials Vol. 29; no. 2; pp. 228 - 238
• Main Authors: Yang, Yiru, Bao, Qipeng, Guo, Lei, Wang, Zhe, Guo, Zhancheng
• Format: Journal Article
• Language: English
• Published: Beijing University of Science and Technology Beijing 01.02.2022; Springer Nature B.V; State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China
• Subjects: Atmosphere; Ceramics; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composites; Computational fluid dynamics; Corrosion and Coatings; Fluid dynamics; Glass; Hydrodynamics; Ironmaking; Materials Science; Mathematical analysis; Mathematical models; Metallic Materials; Natural Materials; Particle size; Reactors; Reduction; Residence time distribution; Surfaces and Interfaces; Thin Films; Tribology; hematite particles; flash reduction; numerical analysis; drop tube reactor
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-020-2210-1

A computational fluid dynamics (CFD) model was developed to accurately predict the flash reduction process, which is considered an efficient alternative ironmaking process. Laboratory-scale experiments were conducted in drop tube reactors to verify the accuracy of the CFD model. The reduction degree of ore particles was selected as a critical indicator of model prediction, and the simulated and experimental results were in good agreement. The influencing factors, including the particle size (20–110 µm), peak temperature (1250–1550°C), and reductive atmosphere (H 2 /CO), were also investigated. The height variation lines indicated that small particles (50 µm) had a longer residence time (3.6 s) than large particles. CO provided a longer residence time (∼1.29 s) than H 2 (∼1.09 s). However, both the experimental and analytical results showed that the reduction degree of particles in CO was significantly lower than that in H 2 atmosphere. The optimum experimental particle size and peak temperature for the preparation of high-quality reduced iron were found to be 50 µm and 1350°C in H 2 atmosphere, and 40 µm and 1550°C in CO atmosphere, respectively.